Code Review
Reviewing the Money Math That Used a Float
The total was computed in binary floating point, so the sum was a cent off on some carts, and the difference only appeared when the decimals did not fit the…
Latest
Opinion
The Standup Is a Status Report and Everyone Knows It
The meeting is defended as coordination and runs as a round of updates, and the gap between the two is why it costs fifteen minutes a person a day and…
Deep Dive
Why the First Kilobytes Are the Slow Ones
A new connection starts with a congestion window of about ten packets and doubles it per round trip, so the first response is gated by the ramp rather than…
Bug Hunt
The Order ID That Lost Its Last Three Digits in JavaScript
The identifier came back from the API as a number, and the number exceeded the safe integer range, so the parsed value rounded, and the lookup found a…
Error Autopsy
The Cron Job That Ran Twice When the Clock Went Back
The hourly job fired on both passes through the repeated hour, so the daily digest went out twice, and the second send was the one the customers complained…
Ecommerce
The Order Created Hook That Fired Before the Payment Cleared
The fulfilment started on the created event, so unpaid orders shipped, and the cancellation arrived after the parcel, and the return postage was the margin…
Security
The JWT That Accepted the none Algorithm
The verifier read the algorithm from the token header and honoured it, so a token signed by nobody was accepted as valid, and the header was the attacker's…
Performance
The Offset Pagination That Scanned Every Row It Skipped
The page query read and discarded ninety thousand rows to return the twenty on page four thousand, and the cost grew with the page number rather than the…
DevOps
The Migration That Could Not Run in a Blue-Green Deploy
The schema change dropped a column the old version still read, so the two versions could not share the database, and the rollback stopped being a switch and…
Tooling
The git bisect Run That Found the Commit in Nine Steps
Three hundred commits sat between the working build and the broken one, and the binary search narrowed it to a single change in nine tests instead of three…
Code Review
Reviewing the Retry That Had No Idempotency Key
The client retried the failed payment request on a timeout, and the original had succeeded, so the retry charged the customer a second time for one order…
Opinion
Your Logs Are a Product and Nobody Owns Them
Everyone writes logs and nobody is responsible for whether they can be read, so the incident arrives and the data exists, and the answer does not, and the…